Cooling device for motors



June 9, 1931. A. J. slr-'FORD ET AL COOLING DEVICE FOR MOTORS FledOGt. 8, 1929 2 SheeS-Sheet l 2e/yawn d.' 7Bm/502g I June 9, 193.1.

A. J, GIFFORD ET AL COOLING DEVICE FOR MOTORS Filed Oct.

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2 Sheets-Sheet 2 Patented June 9, 1931 UNITED vsp'rivrl-:Vs

PATENT OFFICE maar J. Grrronn AND murmur s. r. nrsnor, or smmwsnunv.- xassacnusm'rs, assumons 'ro LELAND-omonn conm, n cpmona'rron or nassacnusm'rs ooonme DEVICE ron xo'rons Application med October 8, 1929. Serial No. 398,207.

This invention relates to the cooling of motors, particularly those used on machine tools,

such as drills and the like.

The principal objects of the invention areto provide a separate fan orcooling the motor connected up so that it will not reverse when the motor reverses and to provide means for Other objects and advantages of the in-A vention will appear hereinafter.

Reference is to be had to the accompanying drawings in which Fig. 1 is a diametrical sectional view of the main motor. and fan motor for a motordriven upright drill constructed in accordance with this invention;

Fig. 2 is a side view of the motor casting, taken in the direction of the arrow 2 in Fig.

1 showing the various outlets;

Fig. 3 is a horizontal sectional view on the line 3 3 of Fig. 2; and

Fig. 4 is a sectional view on the line 4.-4:

of Fig. 3.

y In Fig. 1 is shown the motor connected for driving a drill, the drill not -being illustrated 3 except to show the quill 10 which the motor drives.

The motor is located in a casing 12. The quill 10 which drives a spindle 13 is mounted in anti-friction bearings and vertically arranged, of course, in this casing.

The motor for driving the quill is an ordinary motor having a rotor or core 14 and stationary coils 15 arranged outside the same. This motor as produced in the market is provided with a fan 16 rotating with the rotor and of course, rotating in the reverse direction when the machine is reversed. We have shown this fan in position because it is produced with the motor although it is not a feature of this invention and is of small importance in the cooling and can be dispensed with.

On the. top of the casing 12 is a casing 17 which conducts'air currents and connected with a manifold 18 extending down one side of the motor casing, and has a fan motor casmg 19 on its top.

In this casing'is a motor which may be made the same, as the motor 14-15 and Whlch has two-parts 20 and 21, the former belng a rotor and being mounted on the fanv shaft 22 and is mounted in anti-friction bearlngs as usual.l On the lower end of the fan shaft is a fan 23 within the casing 17. This fan is operated at the desired speed by the motor 2Q-21 and always in the same direction. The connection ofthe two motors with the power is so made that when the machine l motor is reversed they fan motor will continue to rotate inthe proper direction to produce the strongest air currents and in fact, this motor may be so connected up that it is not reversible. The connections for accomplishing these results are not Shown herein as they constitute the subject matter of a diierent invention and it is obvious that the wiring for the two motors can be entirely independ ent.

The air enters the fan 23 through one or more ports 24, passes through the fan and 'l5 through the casing 17 and down the manifold 18. A small part of the air passes through openings 25 into the top of the main motor casing 12, butl most of it passes through a' port 26 into the bottom of an annular air so space 27 which surrounds the motor casing 12, this air space being formed by an outside casing 28. The rest of the air passes through port 29 into the bottom of the motor casing andthe air passes out through outlets 30.

This causes the air to circulate around the motor casing and through the motor both at the top and bottom. The fan 16 assists circulation when the' main motor is running forwardly and retards it a little when running backwardly and can be omitted entirely.

It will be seen 'by reference to Fig. 3 that the space 31 in whichthe wires are located for feeding the motors is also cooled pretty well on one side at the top and also that the air has an opportunity to cool the main motor at all points. This furnishes an elicient means for circulating the cooling air at all times whether the motor is running forwardly or backwardly and the air currents are made 100 `strong enough by the separate fan so that the frearward rotation of the main motor fan 16,

if present, will not seriously affect them.

Although we have illustrated and described only one of the fact that modifications can be made therein by any person skilled in the art Withl v out departing from the scope of the invention as expressed in the claims.

Therefore We do not wish to vbe limited in thisl respect but what we do claim is `Il.' The combination with a main motor, of a fan motor, a fan on the fan-motor shaft, a casing around said fan, means for delivering the air from the fan into the main motor at a plurality of levels, a casingvsurrounding the main motor and having an annular air space around the stator of the main motor and means for. introducing the air currents from the fan into said space andy into the space around the exposed parts of the windings of the stator. p l

2. The combinationwith a main motor, of a fan motor, a fan on the fan motor shaft, a casing around saidifan, means for delivering the air from the `fan into contact with the outer surface of the stator of the main motor at a plurality of levels, one at the bottom and one at the top thereof,rthe. main motor having a casing provided with air outlets at top and bottom opposite the' inlets from the fan.

In testimony whereof we have hereunto axed our signatures.

ALBERT J.l GIFFORD. BENJAMIN T. BISHOP.

orm of the invention we are aware 

